[prog] MySQL & 'IN'

[Dominik Schramm]

Hi Karine,

Karine Proot <kproot at nerim.net> writes:

> SQL-query : 
>
> SELECT sbt_id
> FROM subtypes
> WHERE sbt_id
> IN (
> SELECT tst_id_sbt AS sbt_id

Don't know if that affects the result, but why "AS sbt_id"?
I would try without that; it's not needed since you don't
refer to sbt_id in the subquery.

Are the column types of sbt_id and tst_id_sbt compatible?

Maybe this is some kind of name conflict;
does it work if you rewrite "AS sbt_id" as 
"AS my_sbt_id" or something else that is not identical to
the column name of the main query.

> FROM types_subtypes
> )
> LIMIT 0 , 30
>
> MySQL said: 
>
> #1064 - You have an error in your SQL syntax. [...]
> [...]
> 
> [...] a nice example:
>
> SELECT s1 FROM t1 WHERE s1 IN    (SELECT s1 FROM t2);
>
> Where is the difference ?

The "AS ..." in the query part is the only difference I can see.
However, this is allowed, as these examples here show:
http://dev.mysql.com/doc/mysql/en/Correlated_subqueries.html

hope this helps.
regards,
dominik